BIOFUNCTIONAL ELECTRODE FOR STORING AND RELEASING CONNECTIONS BY SLOW DIFFUSION

Description

Technical field

[0001] The present invention relates to bio-functional devices. The present invention relates, in particular but not exclusively, to the field of analytical devices, such as (bio)sensors, (bio)electrochemical devices, such as (bio)-batteries, and devices for releasing / discharging (bio)chemical / biological compounds. State of the prior art

[0002] In the prior art, biofuel cells are known whose operation requires the addition of (bio)chemical products, such as additives, cofactors or enzyme substrates. Indeed, the biofuel cells of the prior art require that chemical compounds, for example the enzyme or microbial substrate consumed at the anode, be continuously added so that the biofuel cell can operate.

[0003] Also known in the prior art are biosensors comprising a bioreceptor, for example a protein or enzymatic one. The operation of such biosensors is based on the activation or inhibition of the bioreceptor. Activation of the bioreceptor allows, in most cases, specific detection of a particular analyte while inhibition of the bioreceptor allows, in most cases, detection of a group of inhibitory compounds.

[0004] In the prior art, capsules or pills are known for the release / release of compounds, mainly medicinal compounds, in a controlled manner, particularly in an organism. Regarding the capsules, they are mostly submillimeter in size and intended to be introduced directly into a liquid biological environment so as to migrate to a specific target in the organism.

[0005] US 2011 / 076736A1 relates to a bio-functional electrode used in a fuel cell and comprising a storage film which comprises a layer of a support material having at least one inclusion, the at least one inclusion containing a compound of interest.

[0006] One aim of the invention is in particular: to provide a macroscopic sample for storing one or more compounds for subsequent release, and / or to provide a macroscopic sample for storing one or more compounds intended for subsequent release, and / or to provide a macroscopic sample for releasing at the desired time and in a homogeneous, continuous and controlled manner one or more compounds stored in the sample, and / or to provide a macroscopic sample in the form of a film, having a thickness of less than one millimeter, preferably less than 500 microns, which separates two mainly flat faces whose surface area is greater than one square millimeter, preferably greater than one square centimeter, capable of releasing at the desired time and in a homogeneous, continuous and controlled manner one or more compounds stored in the sample,and / or to propose an analytical device intended to be used directly on site and which does not require the addition of any external compound or element to function, and / or to produce electrodes, in particular (bio)anodes, for (bio)batteries, intended to be used directly in any medium, for example biological, and not requiring any addition of products or compounds to function, and / or to produce biosensors, in particular enzymatic ones, intended to be used directly on site and not requiring any addition of products or compounds to function. Presentation of the invention

[0007] The scope of the invention is specified by claims 1, 8 and 9.

[0008] For this purpose, an electrode is proposed comprising: a storage film comprising: a layer of a support material comprising at least one inclusion, the at least one inclusion containing a compound of interest, a wall of sealing material sealing the at least one inclusion, said wall of sealing material being capable of allowing the compound of interest to pass through or diffuse therethrough, a porous layer covering, at least in part, the wall of sealing material, at least part of a surface of the porous layer constituting an active surface of the electrode.

[0009] The at least one inclusion may comprise one or more compounds of interest. The compound(s) of interest may be liquid or solid, for example a powder.

[0010] The wall of the filling material is said to be permeable.

[0011] The wall of the filling material is capable of passing or diffusing the compound of interest through the wall of the filling material.

[0012] According to the invention, the permeable sealing material wall is capable of allowing the compound of interest to pass through the sealing material wall in a controlled manner, for example according to a desired transit or diffusion speed.

[0013] A wall of the at least one inclusion may comprise, or may consist in whole or in part of, the wall of sealing material.

[0014] The at least one inclusion may have a minimum Feret diameter greater than 0.1 µm and a maximum Feret diameter less than the diameter of the inclusion.

[0015] The inclusion is entirely enclosed within the layer of support material. Preferably, the storage film encompasses or envelops the inclusion.

[0016] Preferably, the layer of support material and the wall of sealing material form a single-piece assembly or layer or film. The single-piece assembly or layer or film may constitute the storage film.

[0017] The storage film may be a bio-functional device according to the invention.

[0018] The electrode may comprise a surface, called a release surface, from which the compound of interest is released or released from the storage film, said release surface: comprises, at least in part, a surface of the wall of sealing material, is located opposite the porous layer.

[0019] The porous layer can cover, at least in part, the release surface.

[0020] The release surface may comprise, at least in part, one of the faces or a surface of the storage film. One of the faces or the surface of the storage film may correspond to a portion of the total surface of the storage film.

[0021] The permeable sealing material wall is capable of releasing or releasing the functional compound through the release surface.

[0022] The permeable sealing material wall is capable of allowing the compound of interest to pass through the sealing material wall when, preferably only in the case where, the release surface is in contact with a predetermined medium.

[0023] In the present application, a permeable wall may be understood to mean a wall, a film or a layer of material allowing the free diffusion of one or more species through it.

[0024] The wall of the filling material may be permeable due to: the intrinsic property of the filling material to allow the compound of interest to pass through or diffuse, or the presence of at least one pore, or at least one perforation, in the filling material; the filling material being impermeable, i.e. intrinsically incapable of allowing the compound of interest to pass through or diffuse.

[0025] The wall of sealing material may be permeable, in addition, to one or more predetermined media in which the electrode is intended to be immersed.

[0026] According to the invention, the permeable sealing material wall is capable of releasing or releasing, in a controlled manner, the functional compound via the release surface, for example according to a desired release or release rate. Preferably, the release or release rate is equal to the transit or diffusion rate of the compound of interest through the sealing material.

[0027] Preferably, the compound of interest is released from the release surface into a medium with which the release surface is intended to be brought into contact.

[0028] The porous layer may include a catalyst.

[0029] The catalyst may be inorganic, for example a complex or coordination compound, or organic, for example an enzyme catalyst.

[0030] According to the invention: the sealing material or the sealing material and the support material may be conductive materials, or the storage film may be insulating and / or the porous layer may comprise a porous conductive material and the catalyst.

[0031] The electrode may be intended for use as an electrode of a battery or a bio-battery, for example a bio-fuel cell. The electrode may be intended for use as an electrode of a bio-battery or as an electrode of a biosensor.

[0032] The catalyst may be immobilized in and / or on and / or under the porous conductive material.

[0033] The porous layer may further comprise a permeable trapping material in which the catalyst is contained.

[0034] The permeable trapping material is capable of allowing the compound of interest to pass through, preferably in a controlled manner. The permeable trapping material is capable of allowing ions to pass through, preferably an electrolyte or suitable ions comprising an electrolyte.

[0035] The trapping material may be an electrical insulator.

[0036] The trapping material may comprise an oxidation-reduction mediator, called a redox mediator, capable of passing an electric current through the trapping material. In this case, the porous layer may be a porous conductive layer.

[0037] The trapping material may be a gel and / or a polymer. Preferably, the catalyst is immobilized in the trapping material.

[0038] The trapping material may form a layer or film or may be an array of nano and / or micro and / or macro particles. The film or layer of trapping material may be disposed in and / or on and / or under the porous conductive material. The array of particles forming the trapping material may be disseminated in the porous layer or may be aggregating in an area of ​​the porous layer.

[0039] The at least one inclusion may have the form of a cavity extending into the layer of the support material.

[0040] The electrode may comprise several individual inclusions each having an oblong or round shape extending mainly along the thickness (e) of the storage film.

[0041] Preferably, the thickness (e) of the storage film extends mainly in a direction connecting the storage film to the porous layer.

[0042] The at least one inclusion may constitute at least one individual reservoir enveloped, at least in part, in the layer of support material.

[0043] The storage film may include an encapsulating material at least partially enveloping the at least one inclusion such that a surface of the encapsulating material constitutes at least a portion of a wall of the at least one inclusion.

[0044] The encapsulating material constitutes a film or layer. In addition, the encapsulating material only partially envelops the inclusion.

[0045] The encapsulating material may be made of a different material than the carrier material. The encapsulating material may be the same as the carrier material.

[0046] The encapsulating material may be the same as the sealing material. Preferably, the layer of support material and the film of encapsulating material form an assembly or a single layer or film. The assembly, the single layer or film formed by the layer of support material and the film of encapsulating material may constitute the layer of support material.

[0047] Preferably, the layer of support material, the film of encapsulating material and the wall of sealing material form an assembly or a single-piece layer or film. The assembly, the single-piece layer or film formed by the layer of support material, the film of encapsulating material and the wall of sealing material may constitute the storage film.

[0048] Preferably, the carrier material, the encapsulating material and / or the sealing material are flexible and / or elastic.

[0049] Preferably, the carrier material, the encapsulating material and / or the sealing material is a polymeric material.

[0050] The filling material may be different from the carrier material and / or the encapsulating material.

[0051] The wall of the filling material can be a porous or semi-permeable wall.

[0052] A porous wall can be understood to mean a layer, a film or a wall comprising at least one pore. The pore can be a conduit or a channel passing right through the wall in which it extends.

[0053] A pore diameter or diffusion coefficient may be arranged to obtain a desired rate of release or release of the compound of interest. A rate of release or release of the compound of interest may be a function of the medium in which the electrode is intended to be immersed.

[0054] The filling material can be porous or permeable or semi-permeable.

[0055] The sealing material may be impermeable and may include one or more pores formed in the wall to make the sealing material wall permeable.

[0056] According to the invention, use of the electrode according to the invention as a battery or bio-battery or in a battery or bio-battery is also proposed.

[0057] According to the invention, use of the electrode according to the invention as a sensor or biosensor or in a sensor or biosensor is also proposed.

[0058] According to the invention, use of the electrode according to the invention as a biofunctional device or in a biofunctional device is also proposed.

[0059] According to the invention, there is also provided a method of manufacturing an electrode comprising a storage film, said storage film comprising at least one inclusion, said method comprising the steps of: forming at least one cavity in a layer of a support material, depositing a film of sealing material on the layer of support material to seal the at least one cavity so as to form the at least one inclusion in the layer of support material, forming a porous layer on the film of sealing material; at least a portion of a surface of the porous layer being capable of forming an active electrode surface of the electrode.

[0060] Preferably, the porous layer comprises the porous conductive material and the catalyst.

[0061] The sealing material film can be applied over the carrier material layer.

[0062] Preferably, the at least one inclusion comprises the compound of interest. The compound of interest in powder form may be intended to be released or released by dipping the electrode into a liquid medium. A compound of interest in powder form may have the advantage of being released more slowly than a compound of interest stored in liquid form.

[0063] The compound of interest may be released or released, in a controlled manner, for example when the electrode is immersed in a predetermined liquid. The compound of interest may be released or released, preferably only, when the electrode is immersed in a predetermined liquid.

[0064] The at least one cavity has a minimum Feret diameter greater than 0.1 µm and a maximum Feret diameter less than the diameter of the inclusion.

[0065] The term "sealing material film" may be understood to mean a solid film, a solid strip or a solid layer of material which is deposited on the support material layer. Preferably, the sealing material film is in one piece.

[0066] Preferably, each cavity is included in the layer of support material.

[0067] Preferably, each cavity contains a single orifice to be sealed.

[0068] Each orifice of each cavity can be closed by the wall of filling material.

[0069] Preferably, subsequent to the step of depositing the film of sealing material, the inclusion is sealed by the film of sealing material which constitutes the wall of sealing material.

[0070] The wall of the filling material may be permeable.

[0071] The method may include: prior to the step of forming the at least one inclusion, a step consisting of depositing the layer of support material on a substrate layer, subsequently to the step of depositing the film of sealing material, a step consisting of dissolving the substrate layer so as to obtain the storage film.

[0072] The method may comprise, prior to the step of depositing the film of sealing material, a step consisting of covering a wall of the at least one cavity formed in the layer of support material with a layer of an encapsulating material.

[0073] The wall of the at least one cavity may correspond to the wall of the at least one inclusion, with the exception of the part of the wall of the at least one inclusion formed by the filling material, when the step of covering the wall of the at least one cavity is not implemented.

[0074] The wall of the at least one cavity may be different from the wall of the at least one inclusion when the step of covering the wall of the at least one cavity is implemented. In this case, the encapsulating material may constitute the wall of the at least one inclusion.

[0075] The step of covering a wall of the at least one cavity may comprise a deposition, preferably isotropic, of a layer or film of encapsulating material.

[0076] The method may comprise a step of filling the at least one inclusion with a compound of interest.

[0077] The step of filling the at least one cavity can be implemented prior to the step of depositing the film of sealing material.

[0078] Implementing the filling step prior to the deposition step is particularly suitable for solid compounds of interest but may also be suitable for liquid compounds of interest.

[0079] The step of filling the at least one occlusion can be implemented, subsequent to the step of depositing the film of sealing material, by injecting the compound of interest or a precursor of the compound of interest by means of a capillary or a needle passing through the wall of sealing material.

[0080] The implementation of the filling step subsequent to the deposition step is suitable, in particular, for liquid compounds of interest but may also be suitable for solid compounds of interest.

[0081] Subsequent to the deposition step, the method may comprise a step of making the wall of sealing material permeable by mechanical perforation or by ultrasonic, chemical, optical or plasma treatment of the sealing wall.

[0082] The method may comprise a step of making one or more perforations in the wall of the sealing material; the perforation(s) having a diameter greater than 10 nm.

[0083] The filling step can be carried out concomitantly with the perforation step when the filling step is carried out by injecting the compound of interest or the precursor of the compound of interest by means of a capillary or a needle passing through the wall of the sealing material.

[0084] Preferably, the perforating step is carried out prior to the step of forming a porous layer on the film of sealing material.

[0085] The diameter of the perforation(s) may extend in a direction perpendicular to the thickness of the sealing material wall. The thickness of the sealing material wall may extend in the direction connecting the storage film to the porous layer.

[0086] The step of depositing the porous layer may include the sub-steps of: depositing a porous conductive material on at least a portion of the sealing material wall, then immobilizing a catalyst (8) in and / or on and / or on the porous conductive material; the porous layer comprising the porous conductive material and the catalyst.

[0087] Preferably, the porous conductive material is deposited on at least a portion, preferably all, of the release surface.

[0088] The method may comprise a step of trapping and / or immobilizing the catalyst in a trapping material.

[0089] Subsequently or concomitantly with the step of trapping the catalyst in the trapping material, the method may comprise a step of depositing the trapping material containing the catalyst in and / or on and / or under the porous conductive material.

[0090] The method according to the invention is suitable for implementing the electrode according to the invention. The electrode according to the invention is preferably implemented by the method according to the invention. Preferably, the method according to the invention is specially designed to implement the electrode according to the invention. Thus, any feature of the method according to the invention can be integrated into the electrode according to the invention and vice versa. Description of figures

[0091] Other advantages and particularities of the invention will appear on reading the detailed description of implementations and embodiments which are in no way limiting, and the following appended drawings: [ Fig. 1 ] THE Figures 1A, 1B and 1C are schematic representations of the steps of the method for manufacturing bio-functional devices according to the invention, [ Fig. 2 ] THE Figures 2A, 2B, 2C and 2Dare schematic representations of the steps of the method for manufacturing bio-functional devices according to the invention, [ Fig. 3 ] THE Figures 3A and 3B are schematic representations of electrodes according to the invention, [ Fig. 4 ] there figure 4 is a graph illustrating the evolution of the variation of the molar concentration of methylene blue, released via the release surface, as a function of time for two bio-functional devices according to the invention: a storage film and an electrode, [ Fig. 5 ] there Figure 5 is a graph representing the evolution of the cathodic current, generated by the reduction of orthoquinone to catechol by the electrode according to the invention, as a function of time and the quantity of oxygen dissolved in solution; the electrode, comprising tyrosinase as a catalyst and catechol as a compound of interest, is used as a biosensor to detect dissolved oxygen in solution, [ Fig. 6 ] there figure 6is a graph representing the evolution of the cathodic current, generated by the reduction of orthoquinone to catechol by the electrode according to the invention, as a function of time and the quantity of benzoic acid in solution; the electrode, comprising tyrosinase as a catalyst and catechol as a compound of interest, is used as a biosensor to detect benzoic acid in solution. Description of the embodiments

[0092] The embodiments described below being in no way limiting, it will be possible in particular to consider variants of the invention comprising only a selection of the described characteristics, isolated from the other described characteristics (even if this selection is isolated within a sentence comprising these other characteristics), if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art. This selection comprises at least one characteristic, preferably functional without structural details, or with only a part of the structural details if this part only is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art.

[0093] In reference to the FIGURES 1 And 2, an embodiment of a method of manufacturing a bio-functional device 1 is illustrated. With reference to the FIGURES 3 , an embodiment of an electrode 1 is illustrated. The thickness of the storage film (2) is typically between 50 microns and several centimeters. Preferably, the thickness of the storage film (2) is between 500 µm and 5 mm. The storage film 2 comprises at least one inclusion 4.

[0094] In reference to the FIGURES 1 And 2, the method comprises the step of forming at least one cavity 43 in the layer 3 of support material. The support material is a polymer. By way of non-limiting example, the support material is a flexible (deformable) or rigid (non-deformable) material such as silicon, zinc oxide, aluminum nitride, silicon oxide, aluminum oxide, polymers, plastic materials and metals. Preferably, the support material is made of polyurethane (PU) or polymethyl methacrylate (PMMA). The at least one cavity 43 has a Feret diameter of between 0.05 µm and 5 mm, preferably between 0.1 µm and 1 mm.

[0095] The manufacturing method further comprises the step of depositing the film 5 of sealing material on the layer 3 of support material to seal the at least one cavity 43 so as to form the at least one inclusion 4 in the layer 3 of support material. By way of non-limiting example, the sealing material is made of polyurethane (PU) and therefore impermeable according to the embodiment. The thickness of the film 5 of sealing material is typically between 1 µm and 1 cm, preferably between 25 µm and 400 µm. The sealing material may be chosen from metallic materials, semiconductor materials, piezoelectric materials, insulating materials and polymers such as epoxy resins and biocompatible resins. By way of non-limiting example, the filling material may be PMMA, polyurethane, biocompatible polymers, metal, such as gold for example.The filling material is able to resist the solvent used during the resin dissolution step.

[0096] The method comprises a step of filling the at least one inclusion 4 with a compound of interest which depends on the type of application targeted. The step of filling the at least one cavity 43 is carried out prior to the step of depositing the film 5 of sealing material. The filling step consists of immersing the storage film 2, prior to the step of depositing the film 5 of sealing material, in a solution of compound of interest. Alternatively, the filling step may consist of pouring, prior to the step of depositing the film 5 of sealing material, into the inclusion 4 the compound of interest which is present, for example, in powder form.

[0097] The method comprises a step of making one or more perforations of the wall 5 of sealing material. According to one embodiment, the perforation(s) are made by means of a capillary or a needle by mechanically perforating the wall (5) of sealing material. The perforation(s) have a diameter greater than 10 nm. By way of non-limiting example, the diameter of the perforation(s) is between 100 µm and the Feret diameter of the cavity 43 depending on the intended application as well as depending on the type and solid or liquid state of the compound of interest.

[0098] According to a non-limiting embodiment, the method comprises the step of forming a porous layer 6 on the film 5 of sealing material. The thickness of the porous layer 6 is typically between 400 nm and 20 µm. Preferably, the thickness of the porous layer 6 is typically between 1 and 5 µm. At least a portion of a surface of the porous layer 6 is capable of forming an active surface of the electrode 1.

[0099] The step of depositing the porous layer 6 comprises the step of depositing a porous conductive material 7, carbon nanotubes (CNTs) 7 according to the embodiment, on at least a portion of the wall 5 of sealing material, on the entire sealing wall 5 according to the embodiment. The thickness of CNTs 7 is typically identical to the thickness of the porous layer 6. The step of depositing the porous layer 6 further comprises the step of immobilizing a catalyst 8 in and / or on the CNTs 7. The porous layer 6 therefore comprises the CNTs 7 and the catalyst 8.

[0100] According to the non-limiting embodiment, and with reference to the FIGURE 2B, the method comprises, prior to the step of depositing the film 5 of sealing material, a step consisting of covering a wall 42 of the at least one cavity 43, formed in the layer 3 of support material, with a layer 9 of an encapsulating material made of PU. In this case, the wall 41 of the layer 9 of the encapsulating material constitutes the wall 41 of the inclusion 4 with the exception of the part 412 of the wall 41 of the at least one inclusion 4 formed by the sealing material. The thickness of the layer 9 of encapsulating material is typically greater than 10 nm, preferably between 30 µm and half the Féret diameter of the cavity 43. The encapsulating material may be chosen from metallic materials, semiconductor materials, piezoelectric materials, insulating materials and polymers such as epoxy resins and biocompatible resins.Preferably, the encapsulating material is capable of resisting the solvent used in the resin dissolution step. By way of non-limiting example, the encapsulating material may be PMMA, polyurethane, biocompatible polymers, metal, such as gold for example.

[0101] In reference to the FIGURES 3 , an electrode 1 is described comprising a storage film 2 and a porous layer 6. The storage film 2 comprises a layer 3 of a support material comprising at least one inclusion 4. The at least one inclusion 4 contains at least one compound of interest which differs according to the type of application intended. The storage film 2 further comprises a wall 5 of permeable sealing material sealing the at least one inclusion 4. The wall 5 of permeable sealing material is a porous wall 5.

[0102] According to the embodiment, the electrode 1 is obtained directly by implementing the method described above.

[0103] The at least one inclusion 4 constitutes at least one individual reservoir 4 enveloped, at least in part, in the layer 3 of the support material.

[0104] According to the embodiment, the electrode 1 comprises several individual inclusions 4 each having an oblong shape and extending mainly along the thickness e of the storage film 2.

[0105] The porous layer 6 covers, at least in part, entirely according to the embodiment, the wall 5 of sealing material. At least a part of a surface of the porous layer 6 constitutes an active surface of the electrode 1.

[0106] According to the embodiment, the wall 41 of the at least one inclusion 4, with the exception of the part 412 of the wall 41 of the at least one inclusion 4 formed by the sealing material, is a surface of the support material.

[0107] The electrode 1 comprises a release surface 413 from which the compound of interest is released from the storage film 2. The release surface 413 comprises, at least in part, a surface of the wall 5 of sealing material. The release surface 413 is located opposite the porous layer 6. According to the embodiment, the surfaces of the wall 5 of sealing material located opposite the porous layer 6 and facing the parts 412 of the wall 41 of the sealing material forming parts 412 of walls 41 of the inclusions 4 constitute the release surface 413.

[0108] According to a non-limiting embodiment, the support material is identical to the sealing material. The storage film 2 is therefore insulating according to the embodiment.

[0109] The porous layer 6 comprises a catalyst 8, an electro-catalyst 8 according to the embodiment. The porous layer 6 further comprises a porous conductive material 7, carbon nanotubes (CNTs) 7 according to the embodiment. According to the embodiment, at least a portion of the CNTs 7 constitutes the active surface of the electrode 1.

[0110] According to a non-limiting embodiment illustrated in the FIGURE 3B , the storage film 2 comprises an encapsulating material 9 at least partially enveloping the at least one inclusion 4 so that a surface 411 of the encapsulating material constitutes at least a part of the wall 41 of the at least one inclusion 4.

[0111] In this case, the wall of the at least one inclusion 4, with the exception of the part 412 of the wall 41 of the at least one inclusion 4 formed by the sealing material, is a surface of the film 9 or of the layer 9 of encapsulating material enveloping the inclusion 4.

[0112] According to this non-limiting embodiment, the encapsulating material 9 is PU.

[0113] In reference to the FIGURE 4 , a graph is presented illustrating the variation of the molar concentration of a compound of interest in a solution in which an electrode 1 and a storage film 2 according to the invention are immersed. The compound of interest is methylene blue which is released by the storage film 2 into the solution as a function of time. The release rate and the regularity of the release were evaluated for the storage film 2 according to the invention and for the electrode 1 according to the invention.

[0114] The methylene blue is stored in powder form in the inclusions 4. The step of filling the inclusions 4 was implemented by flowing into the inclusions 4, under the effect of gravity, the methylene blue in powder form. The perforation step was implemented by making, for each inclusion 4, a single perforation of the part 412 of the wall 41 of each inclusion 4 formed by the filling material by means of a needle with a diameter typically equal to 100 µm. The perforation step was carried out by means of an optical microscope and a mechanical needle guidance system.

[0115] Concerning the electrode 1, the step of depositing the CNTs 7 was carried out by depositing a solution (dispersion) of CNTs 7 on the wall 5 of sealing material of a storage film 2 according to the invention. The solution was left for 120 minutes under vacuum on the wall 5 and then rinsed. The concentration of CNTs 7 in the CNT 7 solution is 5 mg / ml. The solvent is ethylene glycol. Solvents such as N,N-dimethylformamide (DMF) or N-methylpyrrolidone (NMP) were prohibited because they denature and deteriorate most of the polymers and therefore the storage film 2 according to the embodiment. After rinsing the storage film 2, the CNTs 7 adhere strongly to the storage film 2, the electrode 1 thus formed is ready for use.

[0116] The storage film 5 was immersed in a volume of 2.5 ml of aqueous solution. The concentration of methylene blue dissolved in the aqueous solution was measured by UV / visible spectrometry. FIGURES 4a and 4b show the evolution of the total concentration of methylene blue in micromoles per liter (µmol / l) in the aqueous solution as a function of time in hours (h). A linear increase in the concentration over time is observed. This indicates a constant release rate. The release rate of the storage film 2 is between 1.5 and 4 µmol / l / h. The release rate of the electrode 1 is between 0.5 and 0.8 µmol / l / h.

[0117] In reference to the FIGURES 5 And 6 , a use as a biosensor of the electrode as presented in the FIGURES 3. According to the embodiment in question, the porous layer 6 comprises CNTs 7, an enzymatic catalyst 8, tyrosinase 8, and a clay, laponite. The compound of interest stored in the inclusion 4, which is gradually released during the use of the electrode 1, is catechol. The filling step was implemented by flowing catechol in powder form into the inclusions 4, under the effect of gravity. The perforation step was implemented by making, for each of the two inclusions 4, a single perforation of the part 412 of the wall 41 of each inclusion 4 formed by the sealing material by means of a needle with a diameter typically equal to 100 µm.

[0118] In practice, the method for implementing the porous layer 6 comprises a dispersion and a delamination of the laponite in an aqueous medium. The laponite is present at a mass concentration of 1 mg / ml. The tyrosinase 8 is then mixed with the aqueous laponite solution at a concentration of 10 mg / ml. The solution comprising the laponite-tyrosinase mixture is then deposited on the electrode 1, comprising a film of CNTs 7 on the wall 5 of sealing material of the storage film 2. The CNTs 7 have been previously deposited on the electrode 1, in accordance with what is described above. The volume of laponite-tyrosinase solution deposited is such that approximately 300 µg of tyrosinase 8 and 30 µg of laponite rest on the CNT 7 film. After deposition of the solution comprising the laponite-tyrosinase mixture, the solvent, i.e. water, is evaporated under vacuum.Electrode 1 is then placed under glutaraldehyde vapor for 45 min in order to crosslink the laponite-tyrosinase mixture. Before using electrode 1, the laponite is gelled by soaking electrode 1 in a hydrogen phosphate / di-hydrogen phosphate buffer solution for 20 min.

[0119] In reference to the FIGURES 5 And 6, the evolution of the cathodic current generated by the electrode used as biosensor 1 is illustrated. For the implementation of the experiment, electrode 1 is immersed in a hydrogen phosphate / di-hydrogen phosphate buffer solution, called buffer solution. In the presence of oxygen and catechol, tyrosinase 8 oxidizes the catechol, which is released at the release surface 413, into ortho-quinone. By applying a voltage of -0.2 Volts, relative to the reference potential of the saturated calomel electrode (SCE), to electrode 1, the appearance of a cathodic current is observed which is generated at electrode 1.

[0120] In reference to the FIGURE 5, the possibility of detecting the presence or absence of dissolved oxygen in solution is illustrated by means of electrode 1. By means of a prior calibration, it is also possible to quantify the quantity of dissolved oxygen in solution. The cathodic current generated at electrode 1 stabilizes at approximately 15 µamperes (µA) after about twenty minutes. After 70 minutes, argon is bubbled into the buffer solution. This has the effect of removing almost all of the dissolved oxygen in the buffer solution and therefore substantially reducing, or even stopping, the activity of tyrosinase 8 and therefore the oxidation of catechol by tyrosinase 8. The quantity of orthoquinone in the porous layer 6 therefore also decreases when the dissolved oxygen concentration decreases. A drop in the cathodic current is then observed to a value close to 0 Amps. The drop in current is proportional to the decrease in the oxygen concentration in solution.This demonstrates that the cathodic current generated at electrode 1 actually comes from the reduction of orthoquinone to catechol by electrode 1.

[0121] In reference to the FIGURE 6, the possibility of detecting the presence of tyrosinase 8 inhibitors, here benzoic acid, is illustrated by means of electrode 1. This inhibitor can be a pollutant. By means of a prior calibration, it is also possible to quantify the quantity of benzoic acid in solution. The cathodic current generated at electrode 1 stabilizes at approximately 7.5 µA after about twenty minutes. After 65 minutes, nine successive injections of known quantities of benzoic acid are carried out in the buffer solution. This has the effect of progressively inhibiting tyrosinase 8, which therefore sees its activity decrease when the benzoic acid concentration increases. The quantity of orthoquinone in the porous layer 6 therefore also decreases when the benzoic acid concentration increases. A stepwise decrease in the cathodic current generated at electrode 1 is observed for each of the benzoic acid injections.The current decreases from 7 µA, the value of the cathodic current before the first injection made at the 65th minute for a benzoic acid concentration of 0 Molar (M), to 3 µA at the 112th minute for a total benzoic acid concentration of 8.10 -4 M. The current drop is proportional to the amount of inhibitor in solution. This demonstrates that the cathodic current generated at electrode 1 actually comes from the reduction of orthoquinone to catechol by electrode 1.

[0122] Thus, in variants which can be combined with each other of the embodiments described above: the sealing material is a permeable material, and / or the wall 5 of sealing material is a semi-permeable wall 5, and / or the sealing material or the sealing material and the support material are conductive materials, and / or the thickness of the porous conductive material 7 is equal to the thickness of the porous layer 6 when the catalyst 8 and the porous conductive material 7 are deposited concomitantly, and / or the substrate layer is made of polyvinyl acetate (PVA) or PMMA, and / or the support material is different from the sealing material, and / or the electrode 1 comprises several individual inclusions 4 each having a round shape, and / or the method comprises: prior to the step of forming the at least one inclusion 4, a step of depositing the layer 3 of support material on a substrate layer, subsequently to the step of depositing the film 5 of sealing material,a step of dissolving the substrate layer so as to obtain the storage film 2, and / or the step of filling the at least one occlusion 4 is implemented, subsequently to the step of depositing the film 5 of sealing material, by injecting the compound of interest or a precursor of the compound of interest by means of a capillary or a needle passing through the wall 5 of sealing material, and / or when the method does not include a step of covering the cavity 43 with a layer 9 of encapsulating material, the wall 42 of the cavity 43 constitutes the wall 41 of the inclusion 4, and / or the perforation of the part 412 of the wall 41 of each inclusion 4 formed by the sealing material is carried out by means of a needle with a diameter greater than 100 µm, and / or the perforation step is implemented by a technique not generating local Joule effect so as not to alter the wall of the sealing material or introduce any inaccuracy as to the size of the pores created,and / or the perforation step is implemented by femto laser or by ultrasonic abrasion.

[0123] In addition, the various features, forms, variations and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive.

Claims

1. Electrode (1) comprising: - a storage film (2) comprising: • a layer (3) of a support material comprising at least one inclusion (4), the at least one inclusion: ▪ contains a compound of interest, ▪ constitutes at least one individual reservoir enveloped, at least partially, in the layer of the support material, ▪ has the form of a cavity extending in the layer of the support material, • a wall (5) of sealing material sealing the at least one inclusion, said wall of sealing material being capable of allowing the compound of interest to pass or diffuse therethrough in a controlled manner, for example according to a desired speed of passage or diffusion, - a porous layer (6) at least partially covering the wall of sealing material, at least a portion of a surface of the porous layer constituting an active surface area of the electrode.

2. Electrode (1) according to claim 1, comprising a surface (413), called release or liberation surface, from which the compound of interest is released or liberated from the storage film (2), said release surface: - comprises, at least partially, a surface of the wall (5) of sealing material, - is situated facing the porous layer (6).

3. Electrode (1) according to claim 1 or 2, in which the porous layer (6) comprises a catalyst (8).

4. Electrode (1) according to any one of the preceding claims, in which: - the sealing material or the sealing material and the support material are conductive materials, or - the storage film (2) is insulating and the porous layer (6) comprises a porous conductive material (7) and the catalyst (8).

5. Electrode (1) according to any one of the preceding claims, comprising several individual inclusions (4) each having an oblong or round shape extending mainly within the thickness (e) of the storage film (2).

6. Electrode (1) according to any one of the preceding claims, in which the storage film (2) comprises an encapsulating material (9) at least partially enveloping the at least one inclusion (4) so that a surface (411) of the encapsulating material constitutes at least a portion of a wall (41) of the at least one inclusion (4).

7. Electrode (1) according to any one of the preceding claims, in which the wall (5) of sealing material is a porous or semi-permeable wall.

8. Use of the electrode (1) according to any one of claims 1 to 7, in a battery or in a sensor.

9. Method for the manufacture of an electrode (1) comprising a storage film (2), said storage film comprising at least one inclusion (4), said method comprising the steps consisting of: - forming at least one cavity (43) in a layer (3) of a support material, - depositing a film (5) of sealing material on the layer (3) of support material to seal the at least one cavity so as to form the at least one inclusion in the layer of support material, said wall of sealing material being capable of allowing the compound of interest to pass or diffuse therethrough in a controlled manner, for example according to a desired speed of passage or diffusion, and the at least one inclusion: ▪ contains a compound of interest, ▪ constitutes at least one individual reservoir enveloped, at least partially, in the layer of the support material, ▪ has the form of a cavity extending in the layer of the support material, - forming a porous layer (6) on the film (5) of sealing material; at least a portion of a surface of the porous layer being capable of forming an electrode active surface area (1).

10. Method according to claim 9, comprising: - prior to the step of formation of the at least one inclusion (4), a step consisting of depositing the layer (3) of support material on a substrate layer, - after the step of deposition of the film (5) of sealing material, a step consisting of dissolving the substrate layer so as to obtain the storage film (2).

11. Method according to claim 9 or 10, comprising, prior to the step of deposition of the film (5) of sealing material, a step consisting of covering a wall (41, 42) of the at least one cavity (43), formed in the layer (3) of support material with a layer (9) of an encapsulating material.

12. Method according to any one of claims 9 to 11, comprising a step consisting of filling the at least one inclusion (4) with a compound of interest.

13. Method according to the preceding claim, in which the step of filling the at least one cavity (43) is implemented prior to the step of deposition of the film (5) of sealing material.

14. Method according to claim 12, in which the step of filling the at least one occlusion (4) is implemented, after the step of deposition of the film (5) of sealing material, by injecting the compound of interest or a precursor of the compound of interest by means of a capillary tube or a needle passing through a wall (5) of sealing material.

15. Method according to any one of claims 9 to 14, comprising a step consisting of producing one or more perforations in the wall (5) of sealing material; the perforation(s) having a diameter greater than 10 nm.

16. Method according to any one of claims 9 to 15, comprising the step consisting of forming a porous layer (6) on the film (5) of sealing material; at least a portion of a surface of the porous layer being capable of forming an active surface area of the electrode (1).

17. Method according to any one of claims 9 to 16, in which the step of deposition of the porous layer (6) comprises the sub-steps consisting of: - depositing a porous conductive material (7) on at least a portion of the wall (5) of sealing material, then - immobilizing a catalyst (8) in and / or on and / or under the porous conductive material; the porous layer comprising the porous conductive material and the catalyst